U.S. patent application number 14/835813 was filed with the patent office on 2016-07-28 for image forming device and non-transitory computer readable medium.
The applicant listed for this patent is FUJI XEROX CO., LTD.. Invention is credited to Masami Furuya, Takeshi Zengo.
Application Number | 20160214421 14/835813 |
Document ID | / |
Family ID | 56433934 |
Filed Date | 2016-07-28 |
United States Patent
Application |
20160214421 |
Kind Code |
A1 |
Furuya; Masami ; et
al. |
July 28, 2016 |
IMAGE FORMING DEVICE AND NON-TRANSITORY COMPUTER READABLE
MEDIUM
Abstract
In the case where, by driving nozzles, test images are formed on
paper so that the area of a width predetermined from an end portion
in an intersecting direction that intersects with a transporting
direction of the paper of a reading area of image reading units is
not included in the test images, and the nozzles in an abnormal
state are detected by using reading data obtained by reading by the
image reading units, the application scope of the reading data
applied for detection of an abnormal state is determined so that
reading data of each of the test images formed by the nozzles as a
detection target of an abnormal state is not repeatedly included
with regard to each nozzle, and the nozzles in an abnormal state
are detected by using the reading data in the determined
application scope.
Inventors: |
Furuya; Masami; (Kanagawa,
JP) ; Zengo; Takeshi; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FUJI XEROX CO., LTD. |
Tokyo |
|
JP |
|
|
Family ID: |
56433934 |
Appl. No.: |
14/835813 |
Filed: |
August 26, 2015 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B41J 2/2146 20130101;
B41J 2/16579 20130101; B41J 29/38 20130101; B41J 2/2142 20130101;
B41J 2/16585 20130101 |
International
Class: |
B41J 29/38 20060101
B41J029/38 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 26, 2015 |
JP |
2015-012400 |
Claims
1. An image forming device, comprising: plural recording elements
that are arranged along an intersecting direction that intersects
with a transporting direction of a recording medium; plural reading
units each including a reading area which extends in the
intersecting direction, and that read plural test images formed by
driving the recording elements using the reading areas, and that
are provided along the intersecting direction so that adjacent end
portions of the reading areas overlap in the transporting
direction, which defines as an overlapping reading area: a forming
unit forms the plural test images by driving the recording elements
as a detection target in an abnormal state, in which a position of
each test image is predetermined in accordance with a standard
position, as a position matching of the recording medium in the
intersecting direction, the position of each test image corresponds
to the reading area on the recording medium, and each test image is
formed so that an area having a width predetermined from an end
portion of the corresponding reading area in the intersecting
direction is not included; a determining unit that in case of
detecting the recording elements in the abnormal state by using
reading data obtained by each reading unit, determines an
application scope of the reading data applied for detecting the
abnormal state so that the reading data of each test image formed
by the recording elements as the detection target does not include
repeatedly data with respect to each recording element; and a
detecting unit that detects the recording elements in the abnormal
state by using reading data in the application scope determined by
the determining unit.
2. The image forming device according to claim 1, wherein the
determining unit determines the application scope (i) by
determining a reading scope in each reading unit so that only one
of parts of the test images recorded by the same recording element
is read by the reading unit, or, (ii) after the parts of the test
images recorded by the same recording element are read by at least
one of the plural reading units, adjusting the reading data so that
one of the parts is included in the application scope.
3. The image forming device according to claim 1, wherein the
standard position is one end portion of the recording medium in the
intersecting direction, the forming unit forms the plural test
images on the recording medium along the intersecting direction so
that adjacent end portions of the test images overlap in the
transporting direction in an area corresponding to the overlapping
reading area, and when a width of an image forming area of the
recording medium in the intersecting direction is greater than the
width of the test image in the intersecting direction formed at the
one end portion, the determining unit determines a size of the test
image formed at a side of the other end portion of the recording
medium in the intersecting direction as the application scope of
the reading data obtained by the reading unit located at the side
of the other end portion.
4. The image forming device according to claim 1, wherein the
standard position is a center part of the reading medium in the
intersecting direction, the forming unit forms the plural test
images so that the test images are not overlapped in the
transporting direction and continue along the intersecting
direction, and the determining unit determines a size of each test
image as the application scope of the reading data obtained by the
corresponding reading unit.
5. The image forming device according to claim 1, wherein the
reading units sequentially reads the plural test images along the
transporting direction for every line extending in the intersecting
direction, the test image includes at least one standard image that
is formed by driving the reading elements continuously arranged
along the intersecting direction as the detection target of the
abnormal state at the same timing, and has a length in the
transporting direction corresponds to a length read by plural times
by the reading unit, and plural detection images that are formed by
driving the reading elements continuously arranged along the
intersecting direction as the detection target of the abnormal
state at different timings and continues to the standard image, the
detecting unit detects the recording elements in the abnormal state
using a detection value and a threshold in accordance with reading
data of the standard image and reading data of the detection
images, and the detecting unit detects the recording elements in
the abnormal state by changing at least one of the detection value
and the threshold so that the greater the difference of timings is
between one end portion and the other end portion of the standard
image in the intersecting direction read by the reading unit, the
less likely the state is determined as the abnormal state.
6. The image forming device according to claim 5, wherein the
forming unit forms the detection images on the recording medium by
dividing the recording elements as the detection target of the
abnormal state into plural recording element groups each of which
has recording elements arranged by spacing for a predetermined
number of recording elements in the intersecting direction, and by
differentiating the timings of driving for every divided recording
element group.
7. The image forming device according to claim 6, wherein the
forming unit alternately forms the standard images and the
detection images on the recording medium in the transporting
direction.
8. The image forming device according to claim 6, wherein a length
of the detection image in the transporting direction respectively
formed by driving each of the plural recording element groups at
different timings corresponds to the length read for plural times
by the reading unit, and the detecting unit detects the reading
elements in the abnormal state by reading each detection image by
the reading unit by increasing the number of times of reading in
response to the difference of the timings between one end portion
and the other end portion of the standard image in the intersecting
direction read by the reading unit being decreased.
9. The image forming device according to claim 5, wherein the
forming unit forms the standard image by driving the plural
recording elements continuously arranged at the position including
the both end portions of the image forming area of the reading
medium in the intersecting direction.
9. image forming device according to claim 9, wherein the forming
unit forms the standard image without driving the recording
elements arranged at a middle part of the both end portions.
11. The image forming device according to claim 5, wherein the
length of the standard image in the transporting direction is set
to a length in which the one end portion and the other end portion
of the standard image are read by one reading by the reading unit
in the state where the reading unit and the reading medium are
relatively inclined in the transporting direction by a
predetermined allowable maximum angle.
12. A non-transitory computer readable medium storing a program of
an image forming device which comprises (i) plural recording
elements that are arranged along an intersecting direction that
intersects with a transporting direction of a recording medium, and
(ii) plural reading units each including a reading area which
extends in the intersecting direction, and that read plural test
images formed by driving the recording elements using the reading
areas, and that are provided along the intersecting direction so
that adjacent end portions of the reading areas overlap in the
transporting direction, which defines as an overlapping reading
area wherein the program causes the image forming device to
function as a forming unit forms the plural test images by driving
the recording elements a detection target in an abnormal state, in
which a position of each test image is predetermined in accordance
with a standard position, as a position matching of the recording
medium in the intersecting direction, the position of each test
image corresponds to the reading area on the recording medium, and
each test image is formed so that an area having a width
predetermined from an end portion of the corresponding reading area
in the intersecting direction is not included: a determining unit
that in case of detecting the recording elements in the abnormal
state by using reading data obtained by each reading unit,
determines an application scope of the reading data applied for
detecting the abnormal state so that the reading data of each test
image formed by the recording elements as the detection target does
not include repeatedly data with respect to each recording element;
and a detecting unit that detects the recording elements in the
abnormal state by using reading data in the application scope
determined by the determining unit.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and claims priority under 35
USC 119 from Japanese Patent Application No. 2015-012400 filed on
Jan. 26, 2015.
BACKGROUND
Technical Field
[0002] The present invention relates to an image forming device and
a non-transitory computer readable medium.
SUMMARY
[0003] An aspect of the present invention provides an image forming
device, comprising: plural recording elements that are arranged
along an intersecting direction that intersects with a transporting
direction of a recording medium; plural reading units each
including a reading area which extends in the intersecting
direction, and that read plural test images formed by driving the
recording elements using the reading areas, and that are provided
along the intersecting direction so that adjacent end portions of
the reading areas overlap in the transporting direction, which
defines as an overlapping reading area; a forming unit forms the
plural test images by driving the recording elements as a detection
target in an abnormal state, in which a position of each test image
is predetermined in accordance with a standard position, as a
position matching of the recording medium in the intersecting
direction, the position of each test image corresponds to the
reading area on the recording medium, and each test image is formed
so that an area having a width predetermined from an end portion of
the corresponding reading area in the intersecting direction is not
included; a determining unit that in case of detecting the
recording elements in the abnormal state by using reading data
obtained by each reading unit, determines an application scope of
the reading data applied for detecting the abnormal state so that
the reading data of each test image formed by the recording
elements as the detection target does not include repeatedly data
with respect to each recording element; and a detecting unit that
detects the recording elements in the abnormal state by using
reading data in the application scope determined by the determining
unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Exemplary embodiments of the present invention will be
described in detail based on the following figures, wherein
[0005] FIG. 1 is a schematic side view that illustrates the
ma.sub.jor configuration of the ink jet recording device related to
each embodiment;
[0006] FIG. 2 is a schematic bottom view that illustrates the
schematic configuration of the recording head related to each
embodiment;
[0007] FIG. 3 is a schematic plan view used for describing the
arrangement state of the image reading unit related to each
embodiment;
[0008] FIG. 4 is a block diagram that illustrates the major
configuration of the electric system of the ink jet recording
device related to each embodiment;
[0009] FIG. 5 is a plan view used for describing one example of a
test image related to a first embodiment;
[0010] FIG. 6 is a plan view used for describing one example of a
standard image and an detection image related to each
embodiment;
[0011] FIG. 7 is a flowchart that illustrates the flow of the
processing of the detection processing program related to the first
embodiment;
[0012] FIG. 8 is a plan view used for describing one example of the
determination processing of the reading scope performed by the
image reading unit related to the first embodiment;
[0013] FIG. 8 is a plan view used for describing one example of the
determination processing of the reading scope performed by the
image reading unit related to the first embodiment;
[0014] FIG. 10 is a flowchart that illustrates the flow of the
processing of the abnormal nozzle determination processing routine
and program related to the each embodiment;
[0015] FIG. 11 is a plan view used for describing one example of
the inclination between the continuous paper and the image reading
unit related to each embodiment;
[0016] FIG. 12 is a plan view used for describing one example of
the reading processing performed by the image reading unit in the
state in which the continuous paper and the image reading unit
related to each embodiment are not inclined to each other;
[0017] FIG. 13 is a plan view used for describing one example of
the reading processing performed by the image reading unit in the
state in which the continuous paper and the image reading unit
related to each embodiment are inclined to each other;
[0018] FIG. 14 is a graph that illustrates one example of the light
intensity for each position of the nozzle related to each
embodiment;
[0019] FIG. 15 is a plan view used for describing one example of
the determination processing of the reading scope performed by the
image reading unit related to a second embodiment;
[0020] FIG. 16 is a flowchart that illustrates the flow of the
processing of the detection processing program related to the
second embodiment;
[0021] FIG. 17 is a plan view used for describing a modification
example of the determination processing of the reading scope
performed by the image reading unit;
[0022] FIG. 18 is a plan view used for describing the modification
example of the determination processing of the reading scope
performed by the image reading unit;
[0023] FIG. 19 is a plan view used for describing the modification
example of the determination processing of the reading scope
performed by the image reading unit;
[0024] FIG. 20 is a plan view used for describing a modification
example of the standard image and the detection image;
[0025] FIG. 21 is a plan view used for describing the modification
example of the standard image and the detection image; and
[0026] FIG. 22 is a plan view used for describing e modification
example g of the standard image and the detection image.
DETAILED DESCRIPTION
[0027] Hereinafter, exemplary embodiments for implementing the
present invention will be described with reference to the
drawings.
First Embodiment
[0028] A first embodiment will be described by referring to the
case where the invention is applied to the ink jet recording device
that records an image by discharging an ink drop on a recording
medium.
[0029] First, with reference to FIGS. 1 to 3, the configuration of
an ink jet recording device 10 related to this embodiment will be
described.
[0030] As illustrated in FIG. 1 the ink jet recording device 10
related to this embodiment includes a transporting roller 20, a
paper feeding roll 30, a rotary encoder 32, a discharging roll 40,
recording heads 50C, 50M, 50Y, and 50K, a drying unit 60, and image
reading units 70A and 70B.
[0031] The transporting roller 20 related to this embodiment
rotates by a transporting motor 22 (refer to FIG. 4) coupled with
the transporting roller 20 through mechanisms such as a gear being
driven. In addition, at the paper feeding roll 30 related to this
embodiment, a long continuous paper P is wound as a recording
medium, and the continuous paper P is transported in the direction
of an arrow A in FIG. 1 in association with the rotation of the
transporting roller 20. Moreover, the transported continuous paper
P is wound at the discharging roll 40. Furthermore, hereinafter,
the direction in which the continuous paper P is transported (the
direction of the arrow A in FIG. 1) is simply referred to as
"transporting direction".
[0032] The rotary encoder 32 related to this embodiment is provided
in the rotation axis of the paper feeding roll 30 and outputs a
clock signal for every time the paper feeding roil 30 is rotated at
a predetermined angle.
[0033] The recording heads 50C, 50M, 50Y, and 50K related to this
embodiment are provided in this order along the transporting
direction from upstream of the transporting direction. In addition,
hereinafter, in the case where there is no need to distinguish
between the recording heads 50C, 50M, 50Y, and 50K, the
alphabetical character at the end of the symbol is omitted.
[0034] Moreover, as illustrated in FIG. 2, the recording heads 50
include plural nozzles 52 arranged along the intersecting direction
that intersects with the transporting direction (hereinafter,
simply referred to as "intersecting direction"). In addition, the
plural nozzles 52 are one example of a recording element of the
present invention. Furthermore, the recording heads 50C, 50M, 50Y,
and 50K discharge ink drops corresponding to each of the four
colors of cyan (C), magenta (M), yellow (Y), and black (K) from the
nozzles 52 on the continuous paper P. In addition, in the ink jet
recording device 10 related to this embodiment, in order to
identify each of the nozzles 52, a nozzle number in the order of 1,
2, . . . is attached to each nozzle 52 from 1.
[0035] The drying unit 60 related to this embodiment, for example,
includes plural surface emission laser elements, dries the ink drop
by applying laser from the surface emission laser elements to the
ink drop discharged onto the continuous paper P to fix the ink drop
to the continuous paper P. In addition, as the drying unit 60,
other devices such as a heater that dries an ink drop discharged
onto the continuous paper P by warm air may be applied.
[0036] Plural (two in this embodiment) image reading units 70A and
70B related to this embodiment are provided from the upstream of
the transporting direction in the order of the image reading unit
70A and the image reading unit 706. In addition, hereinafter, in
the case where there is no need to distinguish between the image
reading units 70A and 70B, the alphabetical character at the end of
the symbol is omitted. Moreover, as illustrated in FIG. 3, the
image reading units 70 related to this embodiment are provided in
the state where each one end portion is protruded in the
intersecting direction only by width W from the end portion in the
intersecting direction (side edge) of the continuous paper P. The
continuous paper P in FIG. 3 is a case illustrated where a
continuous paper in the maximum size in this device is loaded In
the case where a continuous paper smaller than this size is loaded,
the protrusion width at the other end portion side of the
registration position is (the maximum continuous paper size-loaded
continuous paper size+W1), In addition, the image reading units 70
are provided along the intersecting directions so that the area of
the end portions of adjacent reading areas are overlapped in the
transporting direction. Moreover, hereinafter, the scope of the end
portions of the reading areas in the intersecting direction
overlapped in the transporting direction is referred to as a
"reading overlapping scope".
[0037] Specifically, the image reading units 70 are provided so
that the width of the reading overlapping scope is width W2, and
the center part of the width W2 coincides with the center part of
the continuous paper P in the intersecting direction. In addition,
in FIG. 3, the width from the both end portions (dashed line
illustrated in FIG. 3) of an image forming area G of the continuous
paper P in the intersecting direction to the center part of the
continuous paper P in the intersecting direction of is respectively
illustrated as width W3. Moreover, in this embodiment, as an
example, the width W1 is 21 mm, the width W2 is 52 mm, and the
width W3 is 250 mm. Furthermore, in the ink jet recording device 10
related to this embodiment, the width of the image forming area G
in the intersecting direction illustrated in FIG. 3 is the maximum
width of an image formed by the recording head 50 in the
intersecting direction.
[0038] In addition, the image reading unit 70 related to this
embodiment is set as a line sensor including, for example, a
charged coupled device (CCD), a lens, or the like, and reads the
image formed on the continuous paper P along the transporting
direction at the predetermined resolution for each line extending
in the intersecting direction. Moreover, the image reading unit 70
outputs brightness information indicating the light intensity of
each pixel corresponding to the concentration of the read image as
reading data. In addition, in the image reading unit 70, there is a
case where the resolution of the reading is deteriorated as the
image reading unit 70 comes close to the periphery of a lens by an
influence of a deformation at the periphery of the lens according
to the quality of the lens to be used. Here, the image reading unit
70 related to this embodiment is arranged as illustrated in FIG. 3
in order to read the image formed on the continuous paper P at the
area as near as possible to the center part of the image reading
unit 70 in the intersecting direction.
[0039] In addition, as illustrated in FIG. 3, in the ink jet
recording device 10 related to this embodiment, a standard position
(hereinafter referred to as "registration position") for aligning
the position of the continuous paper P in the intersecting
direction is set as one end portion (in the example illustrated in
FIG. 3, the left end portion) of the continuous paper in the
intersecting direction. Moreover, hereinafter, as in this
embodiment, the registration position being the one end portion of
the continuous paper P in the intersecting direction is referred to
as "side registration",
[0040] Next, with reference to FIG. 4, the configuration of the
major parts of the electric system of the ink jet recording device
10 related to this embodiment will be described.
[0041] As illustrated in FIG. 4, the ink jet recording device 10
related to this embodiment includes a central processing unit (CPU)
80 that directs entire operations of the ink jet recording device
10, and a read only memory (ROM) 82 in which various programs and
parameters and the like are stored in advance. In addition, the ink
jet recording device 10 also includes a random access memory (RAM)
84 used as a work area and the like when various programs are
executed by the CPU 80, and a non-volatile recording unit 86 such
as a flash memory.
[0042] Moreover, the ink jet recording device 10 includes a
communication circuit interface (I/F) unit 88 that performs
transmission and reception of communication data with an external
device, Furthermore, the ink jet recording device 10 includes an
operation displaying unit 90 that receives an instruction from the
user with regard to the ink jet recording device 10 and notifies
regarding various pieces of information related to the operation
status and the like of the ink jet recording device 10 to the user.
In addition, the operation displaying unit 90 includes, for
example, a display of a touch panel type which displays a display
button and various pieces of information that realize the reception
of an operation instruction by executing a program, and a hardware
key such as a numeric key or a start button.
[0043] In addition, each of the CPU 80, the ROM 82, the RAM 84, the
storing unit 86, the transporting motor 22, the rotary encoder 32,
and the recording head 50 is coupled with each other through a bus
92 such as an address bus, a data bus, or a control bus. Moreover,
in addition to these, each of the drying unit 60, the image reading
unit 70, the communication circuit I/F unit 88, and the operation
displaying unit 90 is also coupled with each other through the bus
92. Furthermore, in the transporting motor 22, the transporting
roller 20 is coupled.
[0044] According to the above configuration, the ink jet recording
device 10 related to this embodiment respectively accesses the ROM
82, the RAM 84, and the storing unit 86, and transmits and receives
the communication data through the communication circuit I/F unit
88 by the CPU 80. In addition, the ink jet recording device 10
respectively performs acquisition of various data through the
operation displaying unit 90 and display of various pieces of
information with regard to the operation displaying unit 90 by the
CPU 80. Moreover, the ink jet recording device 10 respectively
performs reception of a clock signal output from the rotary encoder
32 and control of the recording head 50, the drying unit 60, and
the image reading unit 70 based on the clock signal by the CPU 80.
Furthermore, the ink jet recording device 10 respectively performs
control of the rotation of the transporting roller 20 through the
transporting motor 22 and acquisition of the brightness output from
the image reading unit 70 by the CPU 80.
[0045] Meanwhile, in the ink jet recording device 10 related to
this embodiment, an abnormal nozzle detection function is equipped
for detecting a nozzle 52 in an abnormal state (hereinafter simply
referred to as "abnormal nozzle"). In addition, the ink jet
recording device 10 forms a test image for detecting the abnormal
nozzle on the continuous paper P in order to realize the abnormal
nozzle detection function. Moreover, for the "abnormal state of the
nozzle 52", a non discharging abnormality in which the ink drop is
not discharged, a thin line abnormality in which the discharge
amount of the ink drop decreases, a deviation abnormality in which
the landing position of the ink drop is deviated, and the like can
be exemplified. In addition, hereinafter, in order to avoid
complication, the case where only the abnormal nozzle of the
recording head 50K is detected will be described, but the same
applies to the recording heads 50C, 50M, and 50Y corresponding to
other colors.
[0046] Moreover, in the ink jet recording device 10 related to this
embodiment, there is a need for determining the application scope
of the reading data of each image reading unit 70 applied to the
detection of the abnormal nozzle (hereinafter simply referred to as
"application scope"), since the test image is read by plural image
reading units 70. Here, in the ink jet recording device 10 related
to this embodiment, an application scope determination function for
determining the application scope is also equipped.
[0047] Next, with reference to FIGS. 5 to 6, the test image of the
ink jet recording device 10 related to this embodiment will be
described. Meanwhile, hereinafter, the case where the entirety of
nozzles 52 are set as the detection target of an abnormal state at
the position corresponding to the width of the image forming area G
in the intersecting direction determined according to the size of
the continuous paper P will be described. In addition, hereinafter,
the nozzle 52 which is the detection target is referred to as
"detection target nozzle".
[0048] First, as illustrated in FIG. 5, the test images T1 and T2
related to this embodiment are formed in the order of the test
image T1 to the test image T2 from the upstream of the transporting
direction. In addition, the test images T1 and T2 related to this
embodiment are set as the images with the same size and shape.
Moreover, hereinafter, in the case where there is no need to
distinguish between the test images T1 and T2, the alphabetical
character at the end of the symbol is omitted. Furthermore, as
illustrated in FIG. 5, test images T related to this embodiment are
formed so that adjacent end portions are overlapped in the
transporting direction inside the reading overlapping scope.
[0049] Specifically, in the test images T, the adjacent end
portions are overlapped in the transporting direction only by the
width W4 in the intersecting direction. In addition, in this
embodiment, the width W4 is set as the width shorter than the width
W2 of the reading overlapping scope, as the width readable by the
image reading unit 70 with the predetermined number of pixels (for
example, 5 pixels) or more, and, specifically, as an example, as 10
mm. Therefore, the width of the test images T in the intersecting
direction related to this embodiment is respectively 255 mm. In
addition, the width W4 being the width readable by the image
reading unit 70 with 5 pixels or more is because an approximation
(hereinafter described in detail) is performed by a second
interpolation. Moreover, the predetermined number of pixels is
adaptable as long as the number is set based on the value of the
resolution of the image reading unit 70 in the intersecting
direction, the value of the width W2, or the like. In addition, the
test images T1 and T2 related to this embodiment are formed at the
position on the continuous paper P in which the area of the width
predetermined from the end portion of the reading area of each of
the image reading units 70A and 70B in the intersecting direction
is not included. Moreover, the predetermined width may be suitably
set based on the amount of the deformation of a lens or the
like.
[0050] Next, as illustrated in FIG. 6, the test images T related to
this embodiment are images in which plural standard images K1 and
detection images K2 of the same number as the standard images K1
are alternately and continuously formed in the transporting
direction. The standard image K1 related to this embodiment is an
image formed by the ink drop discharged from the entirety of the
detection target nozzles. In addition, the length N1 in the
transporting direction of the standard image K1 is set as the
length read plural times by the image reading unit 70.
[0051] The detection images K2 are images formed by dividing the
detection target nozzle into plural nozzles 52 groups in which
plural nozzles 52 arranged with the space for the nozzles 52 of the
predetermined number (in this embodiment, for example, 9) in the
intersecting direction is one group, and by causing every nozzle 52
group to discharge the ink drop. In addition, the detection images
K2 are formed at the position in which the nozzles 52 in the
intersecting direction are deviated for the predetermined number
(in this embodiment, for example, 1), while the timing is different
for each nozzle 52 groups.
[0052] Therefore, the detection images K2 in the first step
illustrated in FIG. 6 are images formed by the nozzles 52 of
10n+1st (n=0, 1, 2 . . . ) based on the nozzles 52 at the position
corresponding to the left end portion of the test images T in FIG.
6 In addition, similarly, the detection images K2 in the second
step illustrated in FIG. 6 are images formed by the nozzles 52 of
10n+2nd (n=0, 1, 2 . . . ) based on the nozzles 52 at the position
corresponding to the left end portion. In other words, the standard
image K1 and the detection images K2 are alternatively and
respectively formed for every amount of 10. In addition, the length
of the detection images K2 in the transporting direction is also
set as the length read by plural times by the image reading unit
70. Moreover, in this embodiment, the image information indicating
the test images T described above (hereinafter referred to as "test
image information) is stored in the storing unit 86 in advance.
[0053] Next, with reference to FIG. 7, the operation of the ink jet
recording device 10 related to this embodiment will be described.
In addition, FIG. 7 is a flowchart illustrating the flow of the
processing of the detection processing program executed by the CPU
80 when an instruction input that instructs regarding the execution
start through the operation displaying unit 90 is input by the
user. In addition, the detection processing program is installed in
the ROM 82 in advance. Moreover, in this embodiment, the timing of
inputting the instruction input that instructs the execution start
is applied, as the timing of executing the detection processing
program, but the timing is not limited thereto. For example, as the
timing of executing the detection processing program, other timings
such as the timing when images of predetermined page numbers are
formed may be applied.
[0054] In a step 200 in FIG. 7, the CPU 80 reads test image
information from the storing unit 86, and specifies the scope of
the number of nozzles that forms the test images T1 and T2 based on
the width of the image forming area G in the intersecting direction
of the continuous paper P and the width of the test images T1 and
T2 in the intersecting direction displayed by the test image
information. In a next step 202, the CPU 80 forms the test images
T1 and T2 on the continuous paper P by driving part of the
recording head 50K, the transporting motor 22, and the like which
are related to the transportation of the continuous paper P based
on the test image information read by the processing of step 200
and the scope of the specified number of the nozzles.
[0055] In a next step 204, the CPU 80 respectively determines the
scopes of reading by the image reading units 70A and 70B as the
application scopes of the reading data of the test images T1 and T2
by the image reading units 70A and 70B.
[0056] The determination processing of the reading scope of the
main step 204 will be described in detail with reference to FIGS. 8
and 9.
[0057] First, as illustrated in FIG. 8, the CPU 80 determines the
scope of the image forming area G in the intersecting direction as
the reading scope by the image reading unit 70A in the case where
the width of the image forming area G in the intersecting direction
is equal to or less than the width of the test images T in the
intersecting direction at the registration position side indicated
by the test image information (that is, the test image T1). In
addition, in this case, the CPU 80 determines that the reading
scope by the image reading unit 70B is 0 (zero). Therefore, in this
case, the reading of the test image T2 by the image reading unit
70B is not performed. Moreover, the reading of the test image T2 by
the image reading unit 70A may not be performed, and the image
reading unit 70A may read the test image T2 and may not perform
abnormal nozzle determination processing to be described later.
[0058] Next, as illustrated in FIG. 9, the CPU 80 determines the
reading scope so that the reading scope of the test image T2 in the
intersecting direction by the image reading unit 70B is the maximum
in the case where the width of the image forming area G in the
intersecting direction is greater than the width of the test images
T in the intersecting direction at the registration position side.
Specifically, as illustrated in FIG. 9, the CPU 80 determines the
width W5 from the end portion at the registration position side of
the test image T1 in the intersecting direction to the end portion
at the registration position side of the test image T2 as the
reading scope by the image reading unit 70A. in addition, in this
case, the CPU 80 determines that the width W6 of the test image T2
in the intersecting direction is the reading scope by the image
reading unit 70B.
[0059] Moreover, hereinafter, in order to avoid complication, the
reading by each image reading unit 70 will be described as being
performed in the reading scope determined by the processing of the
step 204.
[0060] In a step 206 of FIG. 7, the CPU 80 executes the abnormal
nozzle determination processing routine and program, and terminates
a main detection processing program after the abnormal nozzle
determination processing routine and program are terminated.
[0061] Hereinafter, with reference to FIG. 10, an abnormal nozzle
determination processing routine and program related to the
embodiment will be described. In addition, FIG. 10 is the flowchart
that illustrates the flow of the processing of the abnormal nozzle
determination processing routine and program, and the program is
also installed in the ROM 82 in advance.
[0062] In a step 300 of FIG. 10, the CPU 80 performs reading for
every line by the image reading unit 70 until at least any end
portion of one end portion of the standard image K1 in the
intersecting direction by the image reading unit 70 and the other
end portion (in this embodiment, a tip end portion in the
transporting direction) is read. In the case where the CPU 80
detects that at least any one of the one end portion of the image
read by the image reading unit 70 and the other end portion has a
black pixel, the step 300 is determined as positive, and the
process proceeds to the processing of a step 302.
[0063] In the step 302, the CPU 80 substitutes 0 (zero) for a
variable cnt, which is to count the difference between the reading
timing of one end portion by the image reading unit 70 and that of
the other end portion. In a next step 304, the CPU 80 determines
whether the black pixel detected in the step 300 is present in only
the one end portion in the intersecting direction. The CPU 80
proceeds to the processing of a step 306 in the case where this
determination is positive, and proceeds to the processing of a step
310 in the case where the determination is negative.
[0064] In the step 306, the CPU 80 performs reading for every line
by the image reading unit 70 until the remaining end portion of the
standard image K1 in the intersecting direction by the image
reading unit 70 (in this embodiment, the tip end portion in the
transporting direction) is read. In addition, in a step 308, the
CPU 80 performs an increment of the variable cnt one by one for
every reading of one line by the image reading unit 70. In the case
where the CPU 80 detects that the remaining one end portion of the
image read by the image reading unit 70 has a black pixel, the step
306 is determined as positive, and the process proceeds to the
processing of the step 310.
[0065] Here, with reference to FIGS. 11 to 13, the processing from
the step 300 to the step 308 will be described.
[0066] As illustrated in FIG. 11, in the ink jet recording device
10 related to this embodiment, due to an error in the installing
position of the image reading unit 70, the inclinations of the
continuous paper P generated when the continuous paper P is
transported, or the like, there is a case where the test image T is
read by the image reading unit 70 in the state where the image
reading unit 70 and the continuous paper P are relatively inclined
in the transporting direction.
[0067] In FIG. 12, one example in the state where the image reading
unit 70 and the continuous paper P are not relatively inclined in
the transporting direction is illustrated.
[0068] As illustrated in FIG. 12, the length in the transporting
direction of the standard image K1 related to this embodiment is a
length N1. In addition, in the detection image K2 related to this
embodiment, a length M in the transporting direction of each end
portion of the upstream or the downstream in the transporting
direction is each margin, and the part of a length N2 in the
transporting direction in the gaps between each margin is a
detection area used for detecting an abnormal nozzle.
[0069] Hereinafter, as one example, the case where the length N is
2.1 mm, the length M is 0.3 mm, the length N2 is 6.4 mm, and the
length of the reading line in the transporting direction by the
image reading unit 70 is 0.1 mm will be described. As illustrated
in FIG. 12, in the case where the image reading unit 70 and the
continuous paper P are not relatively inclined in the transporting
direction, the CPU 80 detects that the standard image K1 has a
black pixel at the both end portions of the read image in the
intersecting direction at the timing when the standard image K1 is
read for the first time by the image reading unit 70. In addition,
in FIG. 12, the position of the reading line at this timing is
illustrated as a line L1-1. Therefore, in this case, at the timing,
the step 300 is positive, the step 304 is determined as negative,
and the value of the variable cnt is 0 (zero).
[0070] In addition, the CPU 80 detects an abnormal nozzle after the
image for the length N1 and the length M are read by the image
reading unit 70. Specifically, the CPU 80 starts reading the
detection image K2 by the image reading unit 70 after transporting
the continuous paper P for the remained length Ni and the length M
(in the above example, for 2.3 mm) after the both end portions of
the standard image K1 in the intersecting direction are read by the
image reading unit 70. In addition, while the continuous paper P is
transferred for remained length N1 and the length M, the reading by
the image reading unit 70 may be performed or not. In addition, in
FIG. 12, the position of the reading line at the timing when the
reading of the detection image K2 starts is illustrated as a line
L2.
[0071] Meanwhile, in FIG. 13, one example in the state where the
image reading unit 70 and the continuous paper P are relatively
inclined in the transporting direction is illustrated. In addition,
here, as one example, the case where, only for the deviation of 2
mm in the transporting direction (the amount of deviation
illustrated in FIG. 11 is 2 mm) between the position of the one end
portion of the standard image K1 of the reading line and the
position of the other end portion corresponding thereto, the image
reading unit 70 and the continuous paper P are relatively inclined
will be described.
[0072] In this case, as illustrated in FIG. 13, after the left end
portion of the standard image K1 in FIG. 13 is read by the image
reading unit 70, the right end portion of the standard image K1 in
FIG. 13 is read by reading by the 19th image reading unit 70.
Therefore, the value of the variable cnt is 19 at the timing when
the step 306 is determined as positive, and this value indicates
the difference between the reading timing of the left end portion
and that of the right end portion by the image reading unit 70. In
addition, in FIG. 13, the position of the reading line at the
timing where the left end portion is read is illustrated as the
line L1-1, and the position of the reading line at the timing when
the right end portion is read is illustrated as a line L1-2.
[0073] In addition, the CPU 80 starts reading the detection image
K2 after transporting the continuous paper P for the remained
length N1 and the length M (in the above example, for 2.3 mm) after
the right end portion of the standard image K1 is read by the image
reading unit 70. In addition, in FIG. 13, the position of the
reading line at the timing when the reading of the detection image
K2 starts is illustrated as the line L2.
[0074] In a step 310 of FIG. 10, the CPU 80 transports the
continuous paper P for the remaining length N1 and the length M
until the position of the reading line is the position of the line
2 as described above, and proceeds to the processing of a step
312.
[0075] In the step 312, the CPU 80 reads the detection images K2
for one line by the image reading unit 70 and acquires a brightness
information output from the image reading unit 70. In addition, the
CPU 80 acquires the light intensity for each position of the
nozzles 52 in the detection target nozzle by performing the second
interpolation with regard to the light intensity indicated by the
acquired brightness information.
[0076] The processing of the main step 312 will be described with
reference to FIG. 14. A vertical axis of FIG. 14 indicates the
light intensity indicated by the brightness information output from
the image reading unit 70. In addition, in this embodiment, as one
example, the light intensity has a separate value for each notch
from the light intensity 0 to 255 (8 bit configuration). The
greater the value is, the closer the color comes to white, and the
smaller the value is, the closer the color comes to black. In
addition, the vertical axis of FIG. 14 indicates the position of
each nozzle 52 in the intersecting direction in the detection
target nozzle, and a rectangular point plotted in FIG. 14 indicates
the light intensity of each pixel output from the image reading
unit 70.
[0077] In the step 312, the CPU 80 obtains an approximate curve
illustrated in FIG. 14 and derives the light intensity
corresponding to the position of each nozzle 52 by performing
second interpolation with regard to the light intensity of each
pixel indicated by the brightness information output from the image
reading unit 70.
[0078] In a next step 314, the CPU 80 adds the light intensity
added together by the processing of the main step 314 of the
previous time in the repeated processing from a step 312 to a step
316 to the light intensity derived by the previous step 312. In
addition, in the case where the processing of the main step 314 is
performed in the first time in the repeated processing from the
step 312 to the step 316, the CPU 80 adds 0 (zero) and the light
intensity derived by the previous step 312.
[0079] In the step 316, the CPU 80 determines whether or not the
timing when the reading of the detection image K2 is terminated has
been reached. The CPU 80 returns to the processing of the step 312
in the case where the determination is negative, and proceeds to
the processing of a step 318 in the case where the determination is
positive. In addition, in this embodiment, as the timing, a timing
when the reading by the image reading unit 70 only for X times
obtained by a following equation (1) is completed is applied by
using a number of times of reading C and the variable cnt by the
image reading unit 70 required for the reading of the line for the
length N2.
(Equation 1)
X=C-cnt. . . (1)
[0080] Therefore, in the case illustrated in FIG. 12, reading is
performed 64 times (=6.4/0.1) by the image reading unit 70 from the
position of the line L2 to the position of the line L3. In the case
illustrated in FIG. 13, reading is performed 45 times (=64-19) by
the image reading unit 70 from the position of the line L2 to the
position of the line L3.
[0081] In the step 318, the CPU 80 averages the light intensity
added together by the processing from the step 312 to the step 316
being repeatedly performed by dividing the light intensity by the
number of times of reading X of the detection image K2 by the image
reading unit 70.
[0082] In a next step 320, the CPU 80 sets a threshold Y used in a
step 322 to be described so that the greater the difference is
between the timings when the one end portion of the standard image
K1 by the image reading unit 70 in the intersecting direction and
the other portion, the less likely that the state is determined as
abnormal. Specifically, the CPU 80 sets the threshold Y as a great
value as the value of the variable cnt is great.
[0083] In a next step 322, the CPU 80 converts the space (a space D
illustrated in FIG. 14) between the convex peak values on the lower
side the light intensity averaged by the processing of the step 320
into a space for each straight line adjacent to the detection
images K2 based on the resolution of the image reading unit 70. In
addition, the CPU 80 derives the difference between the converted
space and the space between the nozzles 52 corresponding to the
actual device, and determines that the nozzle 52 in a corresponding
position is an abnormal nozzle in the case where the difference is
equal to or more than the threshold Y set by the processing of the
step 320. Moreover, the CPU 80 specifies a nozzle number
corresponding to the abnormal nozzle based on the position of the
nozzle 52 determined to be an abnormal nozzle and the nozzle number
acquired by the processing of the step 200, and stores the nozzle
number in the storing unit 86.
[0084] In addition, in the step 322, the CPU 80 may perform the
determination processing of the abnormal nozzle, not regarding a
peak value of which the light intensity is equal to or more than a
predetermined threshold among the convex peak values on the lower
side, as a peak value. As the threshold in this case, a threshold
set by the user through the operation displaying unit 90 may be
applied, and, for example, the average of the maximum value and the
minimum value of the light intensity averaged by the processing of
the step 318 may be applied.
[0085] In addition, in the step 322, the CPU 80 performs
determination of an abnormal nozzle based on the space for each
straight line adjacent to the detection images K2, but the
determination is not limited thereto. For example, the CPU 80 may
perform determination of an abnormal nozzle based on the position
of the convex peak value on the lower side in the intersecting
direction, of which the standard is the position of the nozzle
number in the intersecting direction acquired, by the processing of
the step 200.
[0086] In a next step 324, the CPU 80 determines whether the
processing from the step 300 to the step 322 is completed in both
of the standard image K1 and the detection image K2. The CPU 80
returns to the processing of the step 300 in the case where this
determination is negative, and proceeds to the processing of a step
326 in the case where the determination is positive.
[0087] In the step 326, the CPU 80 determines whether an abnormal
nozzle is detected by determining whether the nozzle number of the
abnormal nozzle is stored in the storing unit 86. The CPU 80
proceeds to the processing of the step 328 in the case where the
determination is positive.
[0088] In the step 328, the CPU 80 reads the nozzle number of the
abnormal nozzle from the storing unit 86 and informs regarding the
nozzle number by displaying the nozzle number on the operation
displaying unit 90. In addition, in the step 328, the CPU 80 may
perform, for example, maintenance processing such as cleaning
processing with regard to the nozzle number. Moreover, in the step
328, the CPU 80 may set a parameter of the nozzle 52 so that the
size of the ink drop discharged from the nozzle 52 adjacent to the
nozzle with the nozzle number is greater than the common case.
[0089] Meanwhile, the CPU 80 terminates the abnormal nozzle
determination processing routine and program without performing the
processing of the step 328 in the case where the determination in
the step 326 is negative.
[0090] As illustrated above, in this embodiment, in the case where
the width of the image forming area G in the intersecting direction
is greater than the width of the test images T in the intersecting
direction at the registration position side, the reading scope is
determined so that the reading scope in the intersecting direction
is maximum by the image reading unit 70 of the test image T2 formed
at the other end portion side opposite to the registration position
of the continuous paper P in the intersecting direction.
[0091] In contrary for example, a case can be considered where the
entire test image T1 is read by the image reading unit 70A and the
scope of the test image T2 in the intersecting direction that does
not overlap with the test image T1 in the transporting direction is
read by the image reading unit 70B. In this case, according to the
width of the image forming area G in the intersecting direction,
there is a case where the image read by the image reading unit 70B
is, for example, an image formed by the one or two nozzles 52. In
this case, if an abnormal nozzle is included in the nozzles 52, the
abnormal nozzle is not accurately detected. Therefore, in this
embodiment, compared to this case, since the reading scope in the
intersecting direction by the image reading unit 70B is wide, the
reading element in an abnormal state is accurately detected.
[0092] In addition, according to the pixel number of the reading
scope by the image reading unit 70B, there is a case where the
processing of the second interpolation of the step 312 cannot be
performed. In this embodiment, the width W4 is a width read to be
equal to or more than the pixel number (in this embodiment, 5
pixels) predetermined by the image reading unit 70, and the
determination processing of an abnormal nozzle is performed from
the convex peak value on the lower side based on the approximate
curve obtained by the second interpolation, and thus the recording
element in an abnormal state is accurately detected.
[0093] In addition, in this embodiment, detection of an abnormal
nozzle is performed by using the same test image information even
when the width of the image forming area G in the intersecting
direction changes. Therefore, compared to the case where the test
image information is stored for each width of the image forming
area G (that is, for each size of the continuous paper P) in the
intersecting direction, the used amount of the means for storing
(in this embodiment, the storing unit 86) decreases.
[0094] Moreover, in this embodiment, as the relative inclination of
the image reading unit 70 and the continuous paper P is smaller in
the transporting direction, the reading of the detection image K2
by the image reading unit 70 is more frequent. Thereby, compared to
the case where the reading of the detection images K2 by the image
reading unit 70 is performed for the number of times obtained by
assuming the amount of inclination and setting the value as the
fixed value (for example, in this embodiment, 45 times), an
abnormal nozzle is accurately detected. In addition, since the
reading of the detection images K2 is performed by the image
reading unit 70 for plural times, the influence by abnormality such
as unexpected and sporadic ink drop discharge abnormality by the
nozzle 52 can be suppressed.
Second Embodiment
[0095] In the first embodiment, the case where the registration
position of the ink jet recording device 10 is the side
registration is described. In contrast, in a second embodiment, the
case where the registration position of the ink jet recording
device 10 is the center unit of the continuous paper P in the
intersecting direction will be described. Moreover, hereinafter, as
in this embodiment, the registration position being the center part
of the continuous paper P in the intersecting direction is referred
to as "center registration". In addition, since the configuration
of an ink jet recording device 10 related to this embodiment is the
same as in the ink jet recording device 10 related to the first
embodiment (refer to FIGS. 1 to 4), the description thereof will be
omitted here.
[0096] First, with reference to FIG. 15, the test image of the ink
jet recording device 10 that relates to this embodiment will be
described. Meanwhile, also in this embodiment, the case where
entire nozzles 52 at the position corresponding to the width of an
image forming area G in the intersecting direction determined
according to the size of a continuous paper P is a detection target
nozzle will be described.
[0097] As illustrated in FIG. 15, test images T1 and T2 related to
this embodiment are formed in the order of the test image T1 to the
test image T2 from the upstream of a transporting direction. In
addition, the test images T1 and T2 related to this embodiment are
set as the images with the same size and shape. In addition,
hereinafter, in the case where there is no need to distinguish
between the test images T1 and T2, the number at the end of the
symbol is omitted. Furthermore, as illustrated in FIG. 15, test
images T related to this embodiment are formed so that adjacent end
portions are not overlapped in the transporting direction but
continues along an intersecting direction. Moreover, in the test
images T related to this embodiment, the position of the adjacent
portions in the intersecting direction is the same position as the
registration position (the center part of the continuous paper P).
That is the test images T1 and T2 related to this embodiment are
also formed at the position on the continuous paper P in which the
area of the width predetermined from the end portion of the reading
area in the intersecting direction of each of image reading units
70A and 70B is not included.
[0098] Next, with reference to FIG. 16, the operation of the ink
jet recording device 10 related to this embodiment will be
described. In addition, FIG. 16 is a flowchart illustrating the
flow of the processing of the detection processing program executed
by the CPU 80 when an instruction input that instructs regarding
the execution start through the operation displaying unit 90 by the
user is input. In addition, the detection processing program is
installed in the ROM 82 in advance, Moreover, the same step number
as in FIG. 7 is attached to a step in Fig, 16 in which the same
processing is performed as in FIG. 7, and the description thereof
is omitted,
[0099] In a step 205 in FIG. 16, the CPU 80 respectively determines
the scopes of reading by the image reading units 70A and 70B as the
application scopes of the reading data of the test images T1 and T2
by the image reading units 70A and 70B. Specifically, the CPU 80
determines the reading scope by the image reading unit 70A as an
area from the predetermined position in a reading repetition area
(in this embodiment, the registration position) in the intersecting
direction to the position of one end portion of the image forming
area G in the intersecting direction. In addition, the CPU 80
determines the reading scope by the image reading unit 70B as an
area from the predetermined position to the position of the other
end portion of the image forming area G in the intersecting
direction. Therefore, in this embodiment, the test image T1 is read
by the image reading unit 70A, and the test image T2 is read by the
image reading unit 70B.
[0100] Each embodiment is described in the above. However, the
technical scope of the present invention is not limited to the
scope of each embodiment described herein. Various changes or
improvements can be added to each embodiment without departing from
the gist of the invention, and an embodiment to which the changes
or improvements are added is also included in the technical scope
of the present invention.
[0101] In addition, each embodiment does not limit the present
invention pertaining to the claims, and the entire combination of
characteristics described in each embodiment is not necessarily
essential to the means for solving the problem. In each embodiment
described above, various steps of the invention are included, and
the various inventions are extracted by the combination of plural
disclosed components. Even if the several components are removed
from the entire components illustrated in each embodiment, as long
as the effect thereof can be obtained, the configuration in which
the several components are removed is extracted as the
invention.
[0102] For example, in each embodiment, the case where the test
images T in the determined application scope is read by the image
reading unit 70 is described. However, the present invention is not
limited thereto. For example, after the entire test images T in the
reading scope of the image reading unit 70 are read, the
determination processing of an abnormal nozzle with regard to the
reading data obtained by the reading may be performed in the
determined application scope,
[0103] In addition, in each embodiment, the case where two image
reading units 70 are provided is described. However, the present
invention is not limited thereto. For example, three image reading
units 70 may be provided. in FIG. 17, one example in a state where
three image reading units 70 are provided in the first embodiment
is illustrated, and in FIG. 18, one example in a state where three
image reading units 70 are provided in the second embodiment is
illustrated.
[0104] As illustrated in FIG. 17, also in the case where three
image reading units 70 are provided, the CPU 80 determines the
reading scope so that the reading scope of a test image T3 is
maximum by an image reading unit 70C positioned at the other end
portion side opposite to the registration position in the
intersecting direction in the continuous paper P in the step 204 of
the detection processing program.
[0105] Specifically, as illustrated in FIG. 17, in the case where
the registration is the side registration regarding the position,
the CPU 80 determines a width W7 from the end portion at the
registration position side of the test image T1 in the intersecting
direction to the end portion at the registration position side of
the test image T2 in the intersecting direction as the reading
scope by the image reading unit 70A. Specifically, the CPU 80
determines a width W8 from the end portion at the registration
position side of the test image T2 in the intersecting direction to
the end portion at the registration position side of the test image
T3 in the intersecting direction as the reading scope by the image
reading unit 70B. In addition, the CPU 80 determines that a width
W9 of the test image T3 in the intersecting direction is the
reading scope by the image reading unit 70C.
[0106] Moreover, in this embodiment, the CPU 80 may determine a
width W10 of the test image T1 in the intersecting direction as the
reading scope by the image reading unit 70A. In addition, in this
embodiment, the CPU 80 may determine that a width W11 in the
intersecting direction in the scope not overlapping with the test
image T1 and the test image T3 in the transporting direction of the
test image T2 is the reading scope by the image reading unit
70B.
[0107] Meanwhile, as illustrated in FIG. 18, in the case where the
registration is the center registration regarding the position, the
CPU 80 determines the width of the test image T1 in the
intersecting direction as the reading scope by the image reading
unit 70A, and the width of the test image T2 in the intersecting
direction as the reading scope by the image reading unit 70B.
Moreover, the CPU 80 determines that the width of the test image T3
in the intersecting direction is the reading scope by the image
reading unit 70C.
[0108] In addition, in the second embodiment, the case where test
images T1 and T2 are formed in the different positions in the
transporting direction is described. However, the present invention
is not limited thereto. For example, as illustrated in FIG. 19, the
test images T1 and T2 may be formed at the same position as the
transporting direction.
[0109] In addition, in each embodiment, the case where the test
images T includes a standard image K1 and a detection image K2 is
described. However, the present invention is not limited thereto.
For example, in the test images T, the standard image K1 may not be
included but only the detection image K2 may be included. Moreover,
in this case, for example, as the image reading unit 70, an area
sensor may be applied instead of a line sensor.
[0110] In addition, in each embodiment, the case where the standard
image K1 and the detection image K2 are alternately formed is
described. However, the present invention is not limited thereto.
For example, the standard image K1 may be formed only once at the
upstream of the transporting direction of each detection image K2.
In addition, for example, as illustrated in FIG. 20, the standard
image K1 and plural (in an example illustrated in FIG. 20, three)
detection images K2 may be alternately formed.
[0111] In addition, in each embodiment, the case where each
detection image K2 is formed step-wise is described. However, the
present invention is not limited thereto. For example, as
illustrated in FIG. 21, each detection image K2 may be formed in a
zigzag-check shape.
[0112] In addition, in each embodiment, the case where the standard
image K1 is formed by the entire detection target nozzles is
described. However, the present invention is not limited thereto.
For example, as illustrated in FIG. 22, of the detection target
nozzles, the standard image K1 may be formed by only plural nozzles
52 continuously arranged at the both end portions in the
intersecting direction.
[0113] In addition, in each embodiment, the case where the greater
the difference between the timings when one end portion and the
other portion of the standard image K1 in the intersecting
direction are read by the image reading unit 70, the greater a
threshold Y is set to perform the detection of an abnormal nozzle
is described. However, the present invention is not limited
thereto. For example, the threshold Y may not be changed, but a
space D corresponding to the detection image K2 read by the image
reading unit 70 may be changed to be decreased as the difference
between the timings is greater to perform the detection of an
abnormal nozzle. In addition, for example, both the threshold Y and
the space D may be adjusted corresponding to the difference between
the timings.
[0114] In addition, in each embodiment, the case where the image
reading unit 70 and the continuous paper P are relatively inclined
in the transporting direction, and the both end portions of the
standard image K1 in the intersecting direction are read by one
reading by the image reading unit 70 is described. However, the
present invention is not limited thereto. For example, in the state
where the image reading unit 70 and the continuous paper P are
relatively inclined in the transporting direction, the both end
portions of the detection images K2 in the intersecting direction
may not be read by one reading by the image reading unit 70. In
this case, for example, the one end portion of the standard image
K1 in the intersecting direction is first read by the image reading
unit 70. Thereafter, by detecting that a black pixel continues in
the intersecting direction of an image read by the image reading
unit 70, it is detected that the image is the standard image K1.
Moreover, thereafter, the other end portion of the standard image
K1 in the intersecting direction is read by the image reading unit
70. In addition, based on the difference between the reading
timings of the one end portion and the other portion, the number of
times of reading C of the detection image K2 by the image reading
unit 70 and the threshold Y used for detecting an abnormal nozzle
are set as in each embodiment, and an embodiment where the abnormal
nozzle is detected is illustrated.
[0115] In addition, it is not particularly mentioned in each
embodiment, but, before specifying the nozzle number of the
abnormal nozzle, whether the abnormal nozzle exists may be
determined. In this case, for example, between the step 318 and the
step 320 of the abnormal nozzle determination processing routine
and program, the embodiment where the determination processing is
performed that determines whether the abnormal nozzle exists is
illustrated. In addition, as the determination processing of this
embodiment, in the case where the number of the convex peak value
on the lower side and the number of the nozzles 52 used for forming
the detection image K2 corresponding thereto are different, the
embodiment where it is determined that the abnormal nozzle exists
is illustrated. With regard to discharge abnormality, by this
determination, whether the abnormal nozzle exists is
determined.
[0116] In addition, it is not particularly mentioned in each
embodiment, but, based on the difference of the timings of reading
the one end portion and the other end portion of the standard image
K1 in the intersecting direction, the installing position
(inclination angle corresponding to the transporting direction) of
the image reading unit 70 may be corrected.
[0117] In addition, in each embodiment, the case where one long
head is applied as the recording head 50 is described. However, the
present invention is not limited thereto. For example, as the
recording head 50, plural short heads arranged along in the
intersecting direction may be applied.
[0118] In addition, in each embodiment, the case where the present
invention is applied to the ink jet recording device is described.
However, the present invention is not limited thereto. For example,
the present invention may be applied to other image forming devices
such as a light emitting diode (LED) printer.
[0119] In addition, in each embodiment, the case where the
continuous paper P is applied as a recording medium is described.
However, the present invention is not limited thereto. For example,
as a recording medium, a cut paper in a regular form such as A4 or
A3 may be applied. In addition, the material of the recording
medium is not limited to paper, and a recording medium with other
materials may be used.
[0120] In addition, in each embodiment, the case where various
programs are installed in the ROM 82 in advance is described.
However, the present invention is not limited thereto. For example,
the various programs may be provided contained in a storing medium
such as a compact disk read only memory (CD-ROM) or provided
through the network.
[0121] Moreover, in each embodiment, the case where the detection
processing is realized by executing a program by a software
configuration by using a computer is described. However, the
present invention is not limited thereto. For example, the
detection processing may be realized by a hardware configuration,
or the combination of a hardware configuration and a software
configuration.
[0122] Additionally, the configuration of the ink jet recording
device 10 (refer to FIGS. 1 to 4) in each embodiment is one
example, and it is needless to say that the unnecessary part
thereof may be removed or a new part may be added without departing
from the gist of the invention.
[0123] In addition, the flow of the processing of various programs
(refer to FIGS. 7, 10, and 16) in each embodiment is also one
example, and it is needless to say that the unnecessary step
thereof may be removed, a new step may be added, or the processing
order may be switched without departing from the gist of the
invention.
* * * * *